Power supplies have been widely used in a variety of electronic devices. However, there are occasions that no single power supply may meet the requirement of a particular load in a system. To resolve this problem, multiple power converters are combined to convert multiple supply voltages to an output voltage for the load. Such combined multiple power converters are generally referred to as a “multi-input single-output power converter”. In a multi-input single-output power converter, the total power is distributed over the power converters. Specifically, a load current is distributed to the power converters coupled to a common output in a predetermined manner to satisfy the specified power requirements. In the cases of SC1175 of Semtech Corporation and IRU3047 of IR Rectifier Corporation, a master-slave control architecture is utilized in a voltage-mode dual-input single-output power converter, in which a master phase power converter controls the output voltage while a slave phase power converter controls the current distribution as the above mentioned. Particularly, U.S. Pat. No. 6,150,803 to Verga describes a voltage-mode dual-input single-output power converter where sense resistors are coupled in series to the inputs of the power converters of different phases and a difference between a master current and a slave current is used to adjust an error signal of the slave power converter. However, the technique used in this art has the disadvantage of low efficiency since the currents are needed to be detected and then distributed to control the slave power converter and particularly since power dissipation of the resistors reduces efficiency of the overall power converter.
Therefore, it is desired a new control architecture of a multi-input single-output power converter.